Last Updated Aug 2, 2011 9:56 AM EDT
The web allows weird theories about health to spread at lightning speed. The general public is not well-versed in the difference between science and speculation. And, of course, research sometimes does overturn long-held beliefs in favor of new facts.
Here are 10 of the strangest current theories about health and disease. All of them have, at some point, been taken seriously by educated people.